54624-34-9Relevant academic research and scientific papers
Stereoselective Rhodium-Catalyzed Isomerization of Stereoisomeric Mixtures of Arylalkenes
Yang, Hongxuan,Dong, Wenke,Wang, Wencan,Li, Tao,Zhao, Wanxiang
, p. 2833 - 2840 (2020/10/06)
A new efficient method for the synthesis of a high ratio of E -alkenes from E / Z mixtures of alkenes with B 2pin 2in the presence of a rhodium catalyst is described. This reaction features mild reaction conditions, broad functional group tolerance, and highly great application potential.
Intermolecular Radical C(sp3)?H Amination under Iodine Catalysis
Bosnidou, Alexandra E.,Mu?iz, Kilian
supporting information, p. 7485 - 7489 (2019/04/30)
The direct amination of aliphatic C?H bonds has remained one of the most tantalizing transformations in organic chemistry. Herein, we report on a unique catalyst system, which enables the elusive intermolecular C(sp3)?H amination. This practical synthetic strategy provides access to aminated building blocks and fosters innovative multiple C?H amination within a new approach to aminated heterocycles. The synthetic utility is demonstrated by the synthesis of four relevant pharmaceuticals.
Hydroalkylation of terminal aryl alkynes with alkyl diacyl peroxides
Li, Yougui,Ge, Liang,Qian, Bo,Babu, Kaki Raveendra,Bao, Hongli
supporting information, p. 5677 - 5680 (2016/11/28)
A photo and nickel co-catalyzed hydroalkylation of terminal aryl alkynes enabled Z-preferred olefin synthesis has been developed under mild conditions. Alkyl diacyl peroxides were utilized as a new type of alkylation reagents and afforded Z-olefins as the major products in moderate to good yields.
General copper-catalyzed coupling of alkyl-, aryl-, and alkynylaluminum reagents with organohalides
Shrestha, Bijay,Thapa, Surendra,Gurung, Santosh K.,Pike, Ryan A. S.,Giri, Ramesh
, p. 787 - 802 (2016/02/18)
We report the first example of a very general Cu-catalyzed cross-coupling of organoaluminum reagents with organohalides. The reactions proceed for the couplings of alkyl-, aryl-, and alkynylaluminum reagents with aryl and heteroaryl halides and vinyl bromides, affording the cross-coupled products in good to excellent yields. Both primary and secondary alkylaluminum reagents can be utilized as organometallic coupling partners. These reactions are not complicated by β-hydride elimination, and as a result rearranged products are not observed with secondary alkylaluminum reagents even for couplings with heteroaryl halides under "ligand-free" conditions. Radical clock experiment with a radical probe and relative reactivity study of Ph3Al with two haloarenes, 1-bromonaphthalene and 4-chlorobenzonitrile, having two different redox potentials indicates that the reaction does not involve free aryl radicals and radical anions as intermediates. These results combined with the result of the Hammett plot obtained by reacting Ph3Al with iodoarenes containing p-H, p-Me, p-F, and p-CF3 substituents, which shows a linear curve (R2 = 0.99) with a ρ value of +1.06, suggest that the current transformation follows an oxidative addition-reductive elimination pathway.
Analyzing site selectivity in Rh2(esp)2-catalyzed intermolecular C-H amination reactions
Bess, Elizabeth N.,Deluca, Ryan J.,Tindall, Daniel J.,Oderinde, Martins S.,Roizen, Jennifer L.,Du Bois,Sigman, Matthew S.
supporting information, p. 5783 - 5789 (2014/05/06)
Predicting site selectivity in C-H bond oxidation reactions involving heteroatom transfer is challenged by the small energetic differences between disparate bond types and the subtle interplay of steric and electronic effects that influence reactivity. Herein, the factors governing selective Rh 2(esp)2-catalyzed C-H amination of isoamylbenzene derivatives are investigated, where modification to both the nitrogen source, a sulfamate ester, and substrate are shown to impact isomeric product ratios. Linear regression mathematical modeling is used to define a relationship that equates both IR stretching parameters and Hammett σ+ values to the differential free energy of benzylic versus tertiary C-H amination. This model has informed the development of a novel sulfamate ester, which affords the highest benzylic-to-tertiary site selectivity (9.5:1) observed for this system.
Copper-free asymmetric allylic alkylation with a grignard reagent: Design of the ligand and mechanistic studies
Grassi, David,Dolka, Chrysanthi,Jackowski, Olivier,Alexakis, Alexandre
supporting information, p. 1466 - 1475 (2013/02/25)
The Cu-free asymmetric allylic alkylation, catalysed by NHC, with Grignard reagents is reported on allyl bromide derivatives with good results. The enantioselectivity was quite homogeneous (around 85 % ee) on large and various substrates, regardless of the nature of the Grignard reagent. The formation of stereogenic quaternary centres was highly regioselective for both aliphatic and aromatic derivatives with good enantiomeric excess (up to 92 % ee). The methodology developed was found to be complementary with the Cu-catalysed version. Several new NHCs were tested with improved efficiency. In addition, mechanistic studies, using NMR spectroscopy, led to the discovery of the catalytically active species. Copyright
Furanoside phosphite-phosphoroamidite and diphosphoroamidite ligands applied to asymmetric Cu-catalyzed allylic substitution reactions
Magre, Marc,Mazuela, Javier,Dieguez, Montserrat,Pamies, Oscar,Alexakis, Alexandre
experimental part, p. 67 - 71 (2012/05/20)
A phosphite-phosphoroamidite and diphosphoroamidite ligand library was applied in the Cu-catalyzed allylic substitution of a range of cinnamyl-type substrates using several organometallic nucleophiles. Results indicated that selectivity depended strongly on the ligand parameters (position of the phosphoroamidite group at either C-5 or C-3 of the furanoside backbone, as well as the configuration of C-3, the introduction of a second phosphoroamidite moiety, the substituents and configurations in the biaryl phosphite/ phosphoroamidite moieties), the nature of the leaving group of the substrate and the alkylating reagent. Good enantioselectivities (up to 76%) and activity combined with high regioselectivities were obtained.
Silver-catalyzed regioselective carbomagnesiation of alkynes with alkyl halides and Grignard reagents
Kambe, Nobuaki,Moriwaki, Yuusuke,Fujii, Yuuki,Iwasaki, Takanori,Terao, Jun
supporting information; experimental part, p. 4656 - 4659 (2011/10/18)
A silver-catalyzed carbomagnesiation of alkynes with alkyl halides and Grignard reagents afforded alkenyl Grignard reagents regioselectively, where the alkyl group of the alkyl halide, but not that of the Grignard reagent, was introduced into the alkyne.
Catalytic asymmetric carbong-carbon bond formation via allylic alkylations with organolithium compounds
Perez, Manuel,Fananas-Mastral, Martin,Bos, Pieter H.,Rudolph, Alena,Harutyunyan, Syuzanna R.,Feringa, Ben L.
experimental part, p. 377 - 381 (2012/01/06)
Carbon-carbon bond formation is the basis for the biogenesis of nature's essential molecules. Consequently, it lies at the heart of the chemical sciences. Chiral catalysts have been developed for asymmetric C-C bond formation to yield single enantiomers from several organometallic reagents. Remarkably, for extremely reactive organolithium compounds, which are among the most broadly used reagents in chemical synthesis, a general catalytic methodology for enantioselective C-C formation has proven elusive, until now. Here, we report a copper-based chiral catalytic system that allows carbon-carbon bond formation via allylic alkylation with alkyllithium reagents, with extremely high enantioselectivities and able to tolerate several functional groups. We have found that both the solvent used and the structure of the active chiral catalyst are the most critical factors in achieving successful asymmetric catalysis with alkyllithium reagents. The active form of the chiral catalyst has been identified through spectroscopic studies as a diphosphine copper monoalkyl species.
Copper-free asymmetric allylic alkylation with grignard reagents
Jackowski, Olivier,Alexakis, Alexandre
supporting information; experimental part, p. 3346 - 3350 (2010/07/15)
(Chemical Equation Presented) Open wide and say AAA: The copper-free asymmetric allylic alkylation reaction of Crignard reagents, catalyzed by N-heter-ocyclic carbenes, is reported for allyl bromide derivatives. This reaction offers good enantioselectivit
